1. Field of the Invention
The invention herein relates to the cultivation of forests—and horticulture, whereas a germ or a sprout plant is made suitable to be localized in a tube. The tube is specifically designed to prevent so called root twist.
2. Problem to be Solved and description of the Related Art
In order to maintain satisfactory forestry production levels in the future, effective and biological correct methods are required to assure the re-growth of plants after trees are harvested. Re-forestation of forest clearings with financially desirable trees is often hampered when other vegetation competes for the clearings, before the re-forestation has reached the desired results. Within forestry, a number of methods have been developed that provide economically valuable trees with improved conditions to compete with the various types of vegetation in the forest clearings.
Difficulties in finding appropriate conditions where seeds can germinate and grow into plants in forest clearings have led to the need to grow seedlings into plants in artificial environments, for example, nurseries, and only after some time there do the plants become objects for transfer to the suitable cultivation sites. This occurs when the plants have achieved a size that is considered necessary in order for the plants, for example, to survive the competitive situation on promising forest clearings. Today this method of planting has been developed and is generally accepted above all on lands that have conditions for high forestry production. On less productive lands, at least from the forestry production point of view, this planting method has become too expensive.
Many experiments have been carried out in order to find cheaper methods for re-forestation by direct seeding rather than putting out pre-grown plants. The majority of the experiments have been concerned with planting the seedlings at clearings where methods are used to create appropriate growing conditions for the seedling to take root and grow to a small plant and gradually to a tree. The competition from the other vegetation is not generally as bad on poorly producing lands as it is on lands with high production. The interval between harvest and the time when unwanted plants take over in a cleared area becomes longer on weak lands. Thereby, seedlings have a better possibility to develop into established plants before the competing vegetation takes over the clearing.
One of the most difficult problems in growing a new forest directly from the germ stage till reforestation is the creation of appropriate environments for seedlings to grow within a reasonable time frame. There are of course many factors, which contribute to good conditions for seedlings to grow and eventually become established plants. The local habitat has the largest importance for seedling and plant development. Factors of the local habitat are frost, moisture and wind, which come in contact with seedlings and the sprouts. Another factor is the competing vegetation, which in association with fungus and pest such as insects, constitute other difficult factors that hamper the possibilities for seedlings to develop to established plants on a clearing. A third group of factors that influence the result for seedlings and sprouts is rodents and wild animals.
A serious problem that can occurs later in the life of the plant is root twisting, which is a deformation of the root system and is normally caused by improper positioning of the seedling at a nursery bed or by the design of containers in which the seedlings are grown. This can cause severe problems to the developed tree, for example in terms of stability and sensitivity to winds, potentially costing the forest owner substantial amounts.
The cultivation tube of the herein described invention improves in a crucial way the conditions for cultivation of desired tree kind on clearings and significantly reduces the problems with root twist. The invention is characterized by features described in patent SE469105 combined with two new features.
The features described in patent SE469105 are:    A. The cultivation tube includes a fluid absorbing material for absorption of moisture;    B. The cultivation tube includes an evaporation reducing function in order to prevent the moisture to disappear from the tube to    C. The cultivation tube includes a vertically oriented open channel, that links/combines the fluid absorbing material with the atmosphere in order to permit rain and other moisture to enter the tube;
The new features of the invention herein, which is an improvement on that found in the prior art, are:    D. The tube is manufactured of a environmentally friendly material such as a bio-degradable plastic.    E. Tube edge facets/profiles and especially designed tube holes to prevent the twisting of the root system.
The invention gives unique possibilities of choosing a variety of tree kinds and plants for forest development, tailored to varying habitat in the forest clearing, at the same time as root twists are minimized. Forestry in Sweden, for example, is mainly focused on cultivation of coniferous trees such as pine, spruce, and Pinus contorta, and on leafy (deciduous) trees. The invention can of course be used also for other kinds of trees, and also within horticulture, although cultivation tubes and tools in the latter case may be adapted and re-dimensioned. The methods and possibilities for further modifications for specific needs are obvious.